The invention relates to a projectile intended to be fired by a fire-arm.
The invention refers particularly to a projectile consisting of a hard core surrounded by a continuous jacket of ductile material adapted to cooperate with the rifling in the fire-arm.
The prior art embraced various projectiles of this type.
French Patent No. 2 540 239 describes a projectile in which a space is provided between the jacket and the core in order to reduce friction between the projectile and the barrel. Such an arrangement is interesting but does have a number of drawbacks.
A projectile which penetrates a soft body is required to retain its initial shape; on the other hand, if it encounters a hard body, for example an armoured plate, it ought to jettison its jacket in order to pass through the said body. With this type of projectile, the connection between the jacket and the core has been found to be rather poor, with a consequent tendency for the jacket to be stripped off even when the projectile is penetrating a body which is not very hard. Furthermore, when the projectile is set in motion, there is a certain risk of slippage between the core and the jacket which adversely affects the range and accuracy of the projectile.
A similar arrangement is described in French Patent No. 1 240 110 and consequently this suffers from the same faults.
It has likewise been envisaged to produce a projectile in which the core is extended by a frustoconical tail engaged with force into a ductile sleeve. One of the disadvantages of this technique is that upon impact against a hard surface, the jacket spreads out and forms a collar which arrests penetration of the projectile.